/*
 * Copyright (C) 2012 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package okhttp3.mockwebserver;


import java.net.HttpURLConnection;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.logging.Logger;

/**
 * Default dispatcher that processes a script of responses. Populate the script by calling {@link
 * #enqueueResponse(MockResponse)}.
 */
public class QueueDispatcher extends Dispatcher {
    /**
     * Enqueued on shutdown to release threads waiting on {@link #dispatch}. Note that this response
     * isn't transmitted because the connection is closed before this response is returned.
     */
    private static final MockResponse DEAD_LETTER = new MockResponse()
            .setStatus("HTTP/1.1 " + 503 + " shutting down");

    private static final Logger logger = Logger.getLogger(QueueDispatcher.class.getName());
    protected final BlockingQueue<MockResponse> responseQueue = new LinkedBlockingQueue<>();
    private MockResponse failFastResponse;

    @Override
    public MockResponse dispatch(RecordedRequest request) throws InterruptedException {

        // To permit interactive/browser testing, ignore requests for favicons.
        final String requestLine = request.getRequestLine();
        if (requestLine != null && requestLine.equals("GET /favicon.ico HTTP/1.1")) {
            logger.info("served " + requestLine);
            return new MockResponse().setResponseCode(HttpURLConnection.HTTP_NOT_FOUND);
        }

        if (failFastResponse != null && responseQueue.peek() == null) {
            // Fail fast if there's no response queued up.
            return failFastResponse;
        }

        MockResponse result = responseQueue.take();

        // If take() returned because we're shutting down, then enqueue another dead letter so that any
        // other threads waiting on take() will also return.
        if (result == DEAD_LETTER) responseQueue.add(DEAD_LETTER);

        return result;
    }

    @Override
    public MockResponse peek() {
        MockResponse peek = responseQueue.peek();
        if (peek != null) return peek;
        if (failFastResponse != null) return failFastResponse;
        return super.peek();
    }

    public void enqueueResponse(MockResponse response) {
        responseQueue.add(response);
    }

    @Override
    public void shutdown() {
        responseQueue.add(DEAD_LETTER);
    }

    public void setFailFast(boolean failFast) {
        MockResponse failFastResponse = failFast
                ? new MockResponse().setResponseCode(HttpURLConnection.HTTP_NOT_FOUND)
                : null;
        setFailFast(failFastResponse);
    }

    public void setFailFast(MockResponse failFastResponse) {
        this.failFastResponse = failFastResponse;
    }


}
